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Related papers: Low-energy Antiproton Interaction with Helium

200 papers

Data relative to antineutron and antiproton annihilation on large nuclei in the range 75-200 MeV/c present two unexpected features: (a) antineutron and antiproton cross sections have a similar size, (ii) the rise of the antineutron cross…

Nuclear Theory · Physics 2015-02-20 A. Bianconi , E. Lodi Rizzini , V. Mascagna , L. Venturelli

Very low-energy scattering of orthopositronium by helium has been investigated for simultaneous study of elastic cross section and pick-off quenching rate using a model exchange potential. The present calculational scheme, while agrees with…

Atomic and Molecular Clusters · Physics 2009-10-31 Sadhan K. Adhikari , P. K. Biswas , R. A. Sultanov

Total cross sections for single ionization and excitation of molecular hydrogen by antiproton impact are presented over a wide range of impact energy from 1 keV to 6.5 MeV. A nonpertubative time-dependent close-coupling method is applied to…

Atomic Physics · Physics 2015-05-14 Armin Lühr , Alejandro Saenz

The mutual neutralization of H^+ and H^- ions at low collision energies is studied by means of a molecular close-coupling approach. All degrees of freedom are treated at the full quantum level taking into account also the identity of the…

Chemical Physics · Physics 2009-02-12 Michael Stenrup , Åsa Larson , Nils Elander

The Giessen Boltzmann-Uehling-Uhlenbeck transport model with relativistic mean fields is used to simulate $\bar p$-nucleus collisions. Antiproton absorption cross sections and momentum distributions of annihilation products are calculated…

Nuclear Theory · Physics 2009-09-01 A. B. Larionov , I. A. Pshenichnov , I. N. Mishustin , W. Greiner

Metastable antiprotonic helium atoms $^{3,4}\! H\! e\bar pe$ have been discovered recently in experiments of the delayed annihilation of antiprotons in helium media. These exotic atoms survive for an enormous time (about tens of…

Nuclear Theory · Physics 2011-04-15 O. I. Kartavtsev

We compare data of antineutron and antiproton annihilation cross sections on different targets at very low energies. After subtracting Coulomb effects, we observe that the ratio between the antineutron proton and antiproton proton…

Nuclear Theory · Physics 2007-05-23 A. Bianconi , G. Bonomi , M. P. Bussa , G. Gomez , E. Lodi Rizzini , L. Venturelli , A. Zenoni

There are multiple techniques to determine the chemical composition of the ultra-high-energy cosmic rays. While most of the methods are primarily sensitive to the average atomic mass, it is challenging to discriminate between the two…

High Energy Astrophysical Phenomena · Physics 2018-11-14 Ivan S. Karpikov , Grigory I. Rubtsov , Yana V. Zhezher

This talk gives an overview of the recent results on the precision spectroscopy of antiprotonic helium which was performed by the ASACUSA collaboration at the Antiproton Decelerator of CERN. The laser spectroscopy of energy levels of the…

Nuclear Experiment · Physics 2007-05-23 E. Widmann

We have measured the dependence of the relative integral cross section of the reaction Li+HF-->LiF+H on the collision energy using crossed molecular beams. By varying the intersection angle of the beams from 37{\deg} to 90{\deg} we covered…

Chemical Physics · Physics 2011-12-19 Rolf Bobbenkamp , Hansjurgen Loesch , Marcel Mudrich , Frank Stienkemeier

The long range interaction between an antiprotonic helium atom $\bar{p}$He$^+$ and helium atom in its ground state is studied. We calculate the dispersion coefficients $C_6$ using the Complex Coordinate Rotation (CCR) formalism in order to…

Atomic Physics · Physics 2015-12-02 Vladimir I. Korobov , Zhen-Xiang Zhong , Quan-Long Tian

Using an effective interaction approach to describe the interactions between the dark matter particle and the light degrees of freedom of the standard model, we calculate the antiproton flux due to the annihilation of the dark matter in the…

High Energy Physics - Phenomenology · Physics 2011-05-13 Kingman Cheung , Po-Yan Tseng , Tzu-Chiang Yuan

Antiproton scattering off $^3\He$ and $^4\He$ targets is considered at beam energies below 300 MeV within the Glauber-Sitenko approach, utilizing the $\bar N N$ amplitudes of the J\"ulich model as input. A good agreement with available data…

Nuclear Theory · Physics 2013-05-29 Yu. N. Uzikov , J. Haidenbauer , B. A. Prmantaeva

We report on self-consistent calculations of $\bar{p}$ quasi-bound states in selected nuclei performed within the relativistic mean-field (RMF) model employing $\bar{p}$ coupling constants tuned to reproduce $\bar{p}$-atom data. We…

Nuclear Theory · Physics 2017-11-29 Jaroslava Hrtánková , Jiří Mareš

The potential barrier impeding the spontaneous emission of protons in the proton radioactive nuclei is calculated as the sum of nuclear, Coulomb and centrifugal contributions. The nuclear part of the proton-nucleus interaction potential is…

Nuclear Theory · Physics 2015-03-19 T. R. Routray , Abhishek Mishra , S. K. Tripathy , B. Behera , D. N. Basu

We present a geometric interpretation of the so-called annihilation range in reactions of the type $\bar pp \to$ {\em two light mesons} based upon Lorentz effects in the highly relativistic final states ($\gamma=E_{\mathrm{cm}}/2mc^2\simeq…

Nuclear Theory · Physics 2015-06-26 B. El-Bennich , W. M. Kloet

Contrary to the reaction pbar + p --> e+ e- with a high momentum incident antiproton on a free target proton at rest, in which the invariant mass M of the (e+ e-) pair is necessarily much larger than the (pbar p) mass, in the reaction pbar…

Nuclear Theory · Physics 2009-11-19 H. Fonvieille , V. Karmanov

A Semi-classical model is employed to theoretically study mutual neutralization in the collisions of $\mathrm{^4He^+}$ and $\mathrm{H^-}$. The model includes nine covalent states of $\mathrm{^2\Sigma^+}$ symmetry. Here the assumption is…

Atomic and Molecular Clusters · Physics 2018-01-11 Sifiso M. Nkambule , Sibusiso Zwane

The energy losses at collisions of heavy multiplycharged ions with light atoms have been considered under circumstances the ion charge Z>>1 and the relative colliding velocity v>>1, so that Z~v=<c, where c - the light velocity (atomic units…

High Energy Physics - Phenomenology · Physics 2007-05-23 V. I. Matveev , S. G. Tolmanov

Low energy proton capture reactions have been studied in statistical model using the semi-microscopic optical potential in the mass range A=110-125. Nuclear density obtained from relativistic mean field calculation has been folded with…

Nuclear Theory · Physics 2015-06-11 Dipti Chakraborty , Saumi Dutta , G. Gangopadhyay , Abhijit Bhattacharyya